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PubMed2005

Exploration of the optimisation algorithms used in the implementation of adaptive optics in confocal and multiphoton microscopy.

We report on the introduction of active optical elements into confocal and multiphoton microscopes in order to reduce the sample-induced aberration. Using a flexible membrane mirror as the active element, the beam entering the rear of the microscope objective is altered to produce the smallest point spread function once it is brought to a focus inside the sample. The conventional approach to adaptive optics, commonly used in astronomy, is to utilise a wavefront sensor to determine the required mirror shape. We have developed a technique that uses optimisation algorithms to improve the returned signal without the use of a wavefront sensor. We have investigated a number of possible optimisation methods, covering hill climbing, genetic algorithms, and more random search methods. The system has demonstrated a significant enhancement in the axial resolution of a confocal microscope when imaging at depth within a sample. We discuss the trade-offs of the various approaches adopted, comparing speed with resolution enhancement.

Algorithms↗
PubMed2005

Measurement and nature of firing rate adaptation in turtle spinal neurons.

There is sparse literature on the profile of action potential firing rate (spike-frequency) adaptation of vertebrate spinal motoneurons, with most of the work undertaken on cells of the adult cat and young rat. Here, we provide such information on adult turtle motoneurons and spinal ventral-horn interneurons. We compared adaptation in response to intracellular injection of 30-s, constant-current stimuli into high-threshold versus low-threshold motoneurons and spontaneously firing versus non-spontaneously-firing interneurons. The latter were shown to possess some adaptive properties that differed from those of motoneurons, including a delayed initial adaptation and more predominant reversal of adaptation attributable to plateau potentials. Issues were raised concerning the interpretation of changes in the action potentials' afterhyperpolarization shape parameters throughout spike-frequency adaptation. No important differences were demonstrated in the adaptation of the two motoneuron and two interneuron groups. Each of these groups, however, was modeled by its own unique combination of action potential shape parameters for the simulation of its 30-s duration of spike-frequency adaptation. Also, for a small sample of the very highest-threshold versus lowest-threshold motoneurons, the former group had significantly more adaptation than the latter. This finding was like that shown previously for cat motoneurons supplying fast- versus slow twitch motor units.

Action Potentials↗
PubMed2004

Validation of Horne and Ostberg morningness-eveningness questionnaire in a middle-aged population of French workers.

As suggested by the authors, the Horne and Ostberg morning/evening questionnaire (MEQ) has never been adapted to evaluate a nonstudent population. The purpose of this study was to validate this MEQ in a sample of middle-aged workers by modifying only the cutoffs. It was administered in 566 non-shift-workers aged 51.2 to 3.2 years who presented no sleep disorders. According to the Home and Ostberg classification, the sample consisted of 62.1% morning type, 36.6% neither type, and 2.2% evening type. Multiple correspondence analysis, which determines the principal components, was performed on all MEQ items. Then an ascending hierarchical classification was applied to determine 3 clusters from these principal components. On the basis of these 3 clusters, new cutoffs were determined: evening types were considered as scoring under 53 and morning types above 64, thus giving 28.1% morning type, 51.7% neither type, and 20.2% evening type. As an external validation, eveningness was associated with later bedtime and waking-up time (more pronounced at the weekend), greater need for sleep, larger daily sleep debt, greater morning sleepiness, and ease of returning to sleep in the early morning. A positive correlation between age and morningness was again found. This study confirms that "owls" are not rare in a middle-aged sample. We conclude that this adapted MEQ could be useful when investigating age-related changes in sleep.

Biological Clocks↗
PubMed2000

Application of the agar gel precipitin test to detect antibodies to Salmonella enterica serovar enteritidis in serum and egg yolks from infected hens.

Serological surveillance can be an important component for egg quality assurance programs geared toward controlling problems with Salmonella enterica serovar Enteritidis (S. enteritidis) within a flock. Serum is the primary sample source for the procedures, although egg yolk antibody assays have become popularity in recent years. However, these assays tend to be labor intensive, requiring procedures for extracting antibodies from the yolk followed by assaying the samples. We describe an adaptation of the agar gel precipitin (AGP) test for use in detecting antibodies to S. enteritidis deposited in egg yolks of infected hens. Yolk or sera from infected birds were administered to wells cut into seven-well clusters in an agar gel plate, and detection antigen was added to the center well. The agar gels were incubated for 24 h and then examined for the presence of precipitin lines formed by the interaction of antibody with antigen. Three different antigens were tested: S. enteritidis flagella, SEF14 (a 14-kDa fimbrial protein produced ostensibly by S. enteritidis), and a sodium deoxycholate extract of whole S. enteritidis organism. Flagella and the organism extract detected antibodies to S. enteritidis in the yolk and sera, whereas SEF14 was not reactive. Positive reactions were observed in serum 1 wk postchallenge, whereas in yolks, this was further delayed by 1 wk. The sensitivity of the test was slightly less than the standard microagglutination assay, although specificity was slightly higher, as indicated by results from sera and yolks from birds infected with Salmonella enterica serovar Typhimurium. Simplicity and low labor requirements of the assay would allow for the potential testing of several hundred egg samples within a day, which would make up for test shortcomings due to sensitivity. The AGP test could be an important tool for individuals using serological testing to monitor the S. enteritidis situation within their flocks or as a rapid screen for vaccine responses. The assay could also be used in tandem with other AGP tests to screen for the presence of multiple avian pathogens.

Animals↗
PubMed2000

German cross-cultural adaptation of the Health Utilities Index and its application to a sample of childhood cancer survivors.

UNLABELLED: Steady progress in developing effective treatments for childhood cancer and other severe pediatric diseases has established the need to consider the nature and frequency of late physical and psychological effects. The Health Utilities Index Mark 2 and Mark 3 (HUI2/3) systems were developed by Feeny, Furlong, Torrance et al. in Canada. These systems are generic multi-attribute measures of a person's health status and health-related quality of life. The first German version of the Canadian HUI2/3 questionnaire was created in our clinic, following recommended guidelines for cross-cultural adaptation of health-related quality of life measures. The usefulness of the resultant version was investigated using a sample of 142 patients who presented to our oncological outpatients' department for a routine health care visit after completion of treatment. The 15 items of the HUI2/3-questionnaire were answered independently by three groups of assessors--nurses, physicians, and parents or patients. Two additional questions covered ratings of the severity of treatment effects and the specification of these effects. The questionnaire was both easy to use and acceptable to the assessors. Percentage agreement between observers about levels for individual attributes ranged from 56% to 100%, with the lowest agreement on the subjective attributes of emotion, pain and cognition. These results are in accordance with previous studies using the original instrument. HUI2 global utility scores were significantly related to ratings of treatment sequelae, giving support to the discriminant validity of the measure. CONCLUSION: The German version of HUI2/3 is a useful instrument with generally high inter-observer agreement and good suitability for outcome measurement in childhood cancer patients. Further research is needed to assess the usefulness of the instrument in other clinical populations and its sensitivity in longitudinal studies.

Child↗
PubMed1999

Defense mechanisms and personality in depression.

There is a longstanding belief that personality represents a structure that is stable over time, and changes, if at all, very slowly. Nonetheless, clinical and empirical evidence suggests that in patients with some Axis I disorders, the rate of personality disorders using DSM criteria decreases after treatment, suggesting that personality as assessed by phenomenological systems is state-dependent. An alternative to the DSM phenomenological system of conceptualizing personality is the dynamic concept of character, that is, a predictable pattern of both adaptive and pathological defense mechanisms, and personality organization comprised of object relations, ego strengths, and superego development. Data from this study address the hypothesis that defense mechanisms and personality organization remain relatively stable in patients treated for Axis I disorders, irrespective of clinical improvement. Patients meeting DSM-IV criteria for major depressive disorder (MDD) entered randomized, controlled medication trials. Defensive functioning was evaluated with the Defense Style Questionnaire (DSQ) [Bond et al., 1983: Arch Gen Psychiatry 40:333-338], and personality organization was assessed with the Inventory of Personality Organization (IPO; Clarkin et al., unpublished), both at baseline and at the completion of the clinical trial. Data were analyzed for whether an individual's pattern of defense mechanisms and personality organization were stable over time regardless of response to treatment of MDD. The question was also asked whether a predominant pattern of defense mechanisms or level of personality organization predicts response to treatment or dropout rate. Among treatment responders, nonresponders and drop-outs, baseline DSQ scores were similar except for "image-distorting" defenses, which were significantly more prevalent among drop-outs compared to responders (P = .016). Post-treatment DSQ values revealed a significant decrease in "maladaptive" defenses (P = .01) in the entire sample, while intermediate and "adaptive" defenses remained unchanged. This same pattern was found to hold true in treatment responders. When comparing treatment responders and nonresponders at the end of the trial, medication responders used significantly less "maladaptive" defenses than did nonresponders (P = .003), and had a significantly higher, or healthier level of "overall defensive functioning" (P = .04). Baseline and post-treatment IPO values did not show significant differences. Results of the study address the question of whether there are personality characteristics that are enduring and that can be appreciated irrespective of an Axis I disorder.

Adult↗
PubMed2001

[Gap formation features of humid evergreen broad-leaved forest in central subtropical Wawushan Mountain, Sichuan Province, China].

The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720-1750 m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics. The sampling method and canopy formation causes were also discussed. In secondary evergreen broad-leaved forest, the gap density was surprisingly only 9 per hm2 and the size of all gaps was, no more than 10 m2. Almost every gap had only one gap maker, and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap, due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm2, and 56% of the gaps had an area of no more than 40 m2. The largest gap had an area of 256 m2. The canopy gap accounted for 11.1% and expended gap occupied 19.8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105 m2, respectively. Most gaps had more than one gap maker, and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10 yr and a few were formed recently and the estimated gap formation rate was 0.01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography, climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.

Altitude↗
PubMed1988

Psychometric properties of the Social Training Achievement Record (the STAR profile).

Seven hundred and sixty-eight Social Training Achievement Records were collected independently in two settings during routine assessment of mentally handicapped people, mostly adults in hospital. All scales and total scores were highly internally consistent. Factor analysis on one sample yielded two factors named General Adaptive Behaviour and Community and Equipment Skills. This factor structure was replicated on the second sample. This factor solution is highly similar to that reported for the Adaptive Behavior Scale (Nihira, 1976). Two new scales were derived on the basis of these factor analyses which were also highly internally consistent. Parallel forms of these scales were also satisfactorily developed. Total scores and scores on the two new scales were adequate in routine clinical practice and showed good concurrent and criterion group validities. Reliabilities of individual items were less satisfactory. Suggestions for future developments of this scale are made.

Achievement↗
PubMed1993

Enzymatic determination of triglyceride, free cholesterol, and total cholesterol in tissue lipid extracts.

Triglyceride, free cholesterol, and total cholesterol were quantified in lipid extracts of liver and thoracic aorta from nonhuman primates using commercially available enzymatic reagents. Lipids were solubilized in water by the addition of Triton X-100. Results of the enzymatic assays compared favorably with chemical assays of lipids separated by thin-layer chromatography. In addition to saving time, the present method has the advantage of measuring each lipid class from a single sample preparation. Furthermore, the procedure has been adapted for use with microtiter plates that conserve both sample and reagent.

Animals↗
PubMed2001

Detection of Cryptosporidium oocysts in soil samples by enzyme-linked immunoassay.

An ELISA protocol was adapted for detection of Cryptosporidium parvum oocysts in soil samples and the limit of detection of the test was determined. A modified indirect antigen capture ELISA protocol was developed using monoclonal antibodies against the oocyst outer wall. The accuracy of the ELISA was compared to spiked soil samples and measured in terms of sensitivity and specificity of the test. The performance of the ELISA was evaluated in field soil samples and measured using the kappa-statistics. Similarly, the performance of the ELISA was compared to the concentration flotation method, to a modified concentration flotation method and to a commercial ELISA (ProSpecT) in field fecal and soil samples. The limit of detection of the test was selected to be 10,000 oocysts/g. At this limit of detection, the ELISA had a sensitivity of 95% and specificity of 100%. The agreement between the ELISA and the modified flotation-concentration method in detecting Cryptosporidium oocysts in soil samples was 32% (kappa=0.32). The ELISA had the same relative sensitivity (82%) in comparison to both the flotation and ProSpecT in determining Cryptosporidium-infection status of an animal. The kappa-statistics was 0.26 for both tests. The developed ELISA proved to be a valuable diagnostic test for detecting oocysts in soil samples and has a potential application in determining the infection status of animals.

Animals↗
PubMed2026

PScnv: personalized self-normalizing CNV detection with a hierarchical multi-phase framework.

MOTIVATION: Accurate detection of copy number variations (CNVs) from targeted panel sequencing remains challenging due to limited genomic coverage and pronounced sample-specific biases. Existing normalization strategies, including baseline-cohort, matched-control, and single-sample approaches, often struggle to balance noise suppression with adaptability, leading to inconsistent performance across heterogeneous samples. RESULTS: We present PScnv, a personalized self-normalizing framework for robust CNV detection from panel sequencing data. PScnv integrates a pre-built panel-of-normals (PoN) with sample-intrinsic stable chromosomes through ridge-regression normalization to generate individualized log2 ratio profiles with reduced systematic variation. CNVs are then identified using a hierarchical multi-phase segmentation pipeline incorporating z-score pre-partitioning, kernel-based correction, and circular binary segmentation. In 139 clinical tumor samples with orthogonal FISH validation at MET, ERBB2, and MTAP, PScnv showed improved accuracy and robustness over existing methods that do not require patient-matched normal samples, provided that a pre-built PoN cohort is available. AVAILABILITY: Source code is available for academic use at https://github.com/lvws/PScnv.

DNA Copy Number Variations↗
PubMed1999

Properties of a nonparametric test for early comparison of treatments in clinical trials in the presence of surrogate endpoints.

A nonparametric test is derived for comparing treatments with respect to the final endpoint in clinical trials in which the final endpoint has been observed for a random subset of patients, but results are available for a surrogate endpoint for a larger sample of patients. The test is an adaptation of the Wilcoxon-Mann-Whitney two-sample test, with an adjustment that involves a comparison of the ranks of the surrogate endpoints between patients with and without final endpoints. The validity of the test depends on the assumption that the patients with final endpoints represent a random sample of the patients registered in the study. This assumption is viable in trials in which the final endpoint is evaluated at a "landmark" timepoint in the patients' natural history. A small sample simulation study demonstrates that the test has a size that is close to the nominal value for all configurations evaluated. When compared with the conventional test based only on the final endpoints, the new test delivers substantial increases in power only when the surrogate endpoint is highly correlated with the true endpoint. Our research indicates that, in the absence of modeling assumptions, auxiliary information derived from surrogate endpoints can provide significant additional information only under special circumstances.

Biometry↗
PubMed1996

Use of pharmacy computer prescription database to access hypertensive patients for mailed survey research.

OBJECTIVE: To evaluate the use of a pharmacy computer prescription database (PCPD) to identify and sample hypertensive patients outside of their treatment setting for mailed, self-administered survey research comparing the presence and lack of participation incentives and mailed follow-up reminders. SETTING: Two independent, privately owned, free-standing community pharmacies. PARTICIPANTS: A total of 735 individuals identified from a PCPD search who had been prescribed at least 1 of 130 PCPD medications potentially used in hypertensive therapy. METHODS: PCPD was searched by the pharmacist/owner per protocol; participants were sent an individually addressed cover letter on pharmacy letterhead signed by the pharmacist that requested voluntary anonymous completion of an enclosed self-administered, quality-of-life opinion survey; the first search used no incentive or follow-up; the second search used an incentive and mailed a follow-up reminder. Research protocol followed published ethics guidelines. RESULTS: There was a mean 84% return with incentive and follow-up strategies compared with a mean 25% return without strategies (p < 0.01) for all drug groups between searches; no statistical difference in response was shown between the same drug groups (alpha 1-blockers, calcium-channel blockers, and centrally acting alpha 2-agonists) within searches. CONCLUSIONS: Acceptable response rates (74-93% return) can be obtained with traditional follow-up mailed incentives, prescription issuance within 6 months, incentives to both hypertensive and nonhypertensive responders, and sampling strategies within potential drug groups. Methodology can be adapted to other populations by alternative drug sampling strategies.

Adult↗
PubMed1983

Direct determination of sodium and potassium in blood serum by flow injection and atomic absorption spectrophotometry.

A simple and reliable method for the measurement of sodium and potassium in blood serum without any sample dilution by using flow injection and atomic absorption spectrophotometry is described. A sample throughout of 100 measurements per hour is possible. Matrix problems have not been encountered. The coefficient of variation for within-run determinations is about 1,14 and 2,36% for sodium and potassium, respectively, in serum samples (n = 10). The method is easily adaptable to pediatric research, because of the low required sample volume of 5 microliter.

Blood Specimen Collection↗
PubMed1998

Research note: investigation on the metabolism of glycerol in the rumen of bulls.

Two bulls, each fitted with rumen and duodenal cannulas, received (in addition to a hay-grain diet) twice daily an infusion of 200 g glycerol into the rumen over a period of six days. During this preliminary in vivo investigation, the influence of a glycerol application on the rumen environment over a six-day adaptation period was examined. Samples of rumen fluid were collected daily, two hours after glycerol infusion. An additional 15N-urea application into the rumen was given on days 1 (without glycerol infusion), 3 and 7 (with glycerol infusion). Extra samples of rumen fluid and blood plasma (from puncture of vena jungularis) were taken through the 12th hour following urea application. Rumen fluid pH was reduced due to glycerol intake from 6.3 (day 1, without glycerol) to 5.4 by day 7. Molar proportion of acetic acid to propionic acid decreased from 3.5 (day 1) to 2.1 (days 6 and 7). Average glycerol disappearance rate from the rumen was 4.7 gl-1 h-1 for the first hour. Only small amounts of glycerol could be detected in the duodenal digesta. Blood plasma glycerol content was significantly higher after glycerol application (0.061 mmol l-1 vs. 0.019 mmol l-1). The incorporation of 15N into the rumen bacteria and the proportion of bacterial N (as percent of TCA-precipitable N in the rumen fluid) were lower after glycerol influsion. These results, coupled with the lower concentration of iso-acids (isobutyric and isovaleric acids) in the rumen fluid, indicate that the high amount of glycerol infusion (10% of DMI) reduced protein metabolism of rumen bacteria throughout the experimental period.

Adaptation, Physiological↗
PubMed1995

Socioeconomic disadvantage, proximal environmental experiences, and socioemotional and academic adjustment in early adolescence: investigation of a mediated effects model.

This study investigated interrelations among conditions of household socioeconomic disadvantage, proximal environmental experiences, and adaptational outcomes in a sample of 398 middle grade, early adolescents from a predominantly poor, rural area. Findings indicated that levels of disadvantage were related to both socioemotional and academic adjustment, with those from relatively disadvantaged backgrounds faring most poorly. Specifically, youth from homes in which adults were employed in low-income, unskilled occupations were found to have lower levels of school performance and achievement compared to those from homes in which adults were employed in higher paying semi-skilled or skilled/professional occupations. Further, youth from families in which neither parent had graduated from high school exhibited significantly worse socioemotional and academic adjustment than did those whose parents had higher educational levels. Youth who lived in relatively disadvantaged homes also reported more negative experiences of proximal environmental conditions relating to family and school contexts and greater exposure to stressful life events. Most notably, findings provided support for employing an ecological-mediational perspective to understand patterns of linkage between socioeconomic disadvantage and levels of adjustment. Support for this viewpoint included the finding that proximal environmental experiences were significant predictors of adolescent adjustment, independent of shared variance with conditions of household disadvantage, whereas conditions of disadvantage in several instances were no longer related significantly to indices of adjustment once their association with proximal environmental conditions was taken into account. The discussion considers implications for the targeting and scope of ecologically oriented approaches to preventive intervention.

Achievement↗
PubMed1998

6-month use of 0.2% delmopinol hydrochloride in comparison with 0.2% chlorhexidine digluconate and placebo (II). Effect on plaque and salivary microflora.

This double-blind, randomised, 6-month clinical trial with parallel group design in 68 subjects with gingivitis was conducted to study the effects on the oral flora of delmopinol hydrochloride 2 mg/ml (0.2% w/v, Decapinol Mouthwash), when used for partly supervised mouthrinsing in comparison with placebo and chlorhexidine digluconate 2 mg/ml (0.2% w/v, Hibitane Dental, ICI Pharmaceuticals, UK). Apart from estimating the total cultivable microbial dental plaque flora and salivary flora, analyses were focused on bacterial groups associated with gingivitis/periodontitis and dental caries. Furthermore, the presence of staphylococci, gram-negative enteric bacteria and yeasts in saliva were evaluated. The minimal inhibitory concentration (MIC) was determined for isolates belonging to the predominating micro-organisms in samples of both dental plaque and saliva. In relation to the findings in the placebo group, the use of delmopinol during the rinsing period did not produce an undesirable shift in the bacterial populations considered to be related to dental caries or periodontal diseases. These groups remained virtually unchanged during the study. In relation to the observations in the placebo group, slight reductions in the total cultivable plaque and salivary flora were observed during the study and no change was found in the ratio total anaerobically/aerobically cultivable microbial flora. Furthermore, no increased growth in staphylococci, enteric bacteria or yeasts was observed in the saliva samples. The pattern of changes taking place in the composition of the plaque and salivary microbial flora in samples from the participants rinsing with chlorhexidine were in most aspects similar to that observed in the delmopinol group. In the delmopinol group, no microbiologically significant changes were observed over time in the MIC-values for the isolates, neither in the plaque nor in the saliva samples, which indicates that no adaptation to delmopinol had taken place during the rinsing period. Similar observations were made for the plaque isolates in samples from the participants in the chlorhexidine group. On the other hand, when gram-positive and catalase-negative cocci from the saliva samples of the latter group were tested against chlorhexidine, 4-6 times higher MIC-values were obtained at 3 and 6 months both when compared to baseline and in comparison with the other two rinsing groups (p<0.01 or p<0.05). Neither delmopinol nor chlorhexidine showed any residual effect on the studied microbial groups in the plaque and the saliva samples 3 months after the end of treatment. In conclusion, delmopinol was accompanied by a composition of the plaque and salivary flora associated with healthy conditions in the oral cavity.

Bacteria↗
PubMed2024

Heat Inactivation of Nipah Virus for Downstream Single-Cell RNA Sequencing Does Not Interfere with Sample Quality.

Single-cell RNA sequencing (scRNA-seq) technologies are instrumental to improving our understanding of virus-host interactions in cell culture infection studies and complex biological systems because they allow separating the transcriptional signatures of infected versus non-infected bystander cells. A drawback of using biosafety level (BSL) 4 pathogens is that protocols are typically developed without consideration of virus inactivation during the procedure. To ensure complete inactivation of virus-containing samples for downstream analyses, an adaptation of the workflow is needed. Focusing on a commercially available microfluidic partitioning scRNA-seq platform to prepare samples for scRNA-seq, we tested various chemical and physical components of the platform for their ability to inactivate Nipah virus (NiV), a BSL-4 pathogen that belongs to the group of nonsegmented negative-sense RNA viruses. The only step of the standard protocol that led to NiV inactivation was a 5 min incubation at 85 &#xb0;C. To comply with the more stringent biosafety requirements for BSL-4-derived samples, we included an additional heat step after cDNA synthesis. This step alone was sufficient to inactivate NiV-containing samples, adding to the necessary inactivation redundancy. Importantly, the additional heat step did not affect sample quality or downstream scRNA-seq results.

Nipah Virus↗